Method of manufacturing artificial silk filaments



Patented Dec. 5, 1933 lTED STATES PATENT OFFICE METHOD OF MANUFACTURINGARTIFICIAL SILK FILAMIENTS tion of Delaware No Drawing. Application July31, 1929 Serial No. 382,576

4 Claims. (01. 106-40) Our invention relates to the manufacture ofartificial silk filaments by a method in which fine particles of aninorganic pigment-like material are thoroughly incorporated with anddistributed throughout the mass material of a solution of a cellulosecompound preparatory to forming said material into an artificial silkfilament by forcing it through a small orifice.

Broadly speaking, such process is described and claimed in U. S. patentsof James, A. Singmaster, No. 1,725,742, granted August 20,- 1929, andNo. 1,875,894, granted September 6, 1932. In said patents the characterof inorganic pigment-like materials adapted for use and tending toproduce a filament of a desirable opacity, covering power and luster areset out and certain methods are described for securing-a thoroughdistribution of the pigment-like particles in the solution and producedfilaments.

The object of our invention is to provide an efiective method forsecuring a thorough distribution of the pigment-like particles in lowviscosity spinning solutions of cellulose compounds, such, for example,as those found in the usual processes of manufacturing artificial silkfrom viscose and cuprammonium solutions, and in the nitrocellulose andcellulose-acetate processes when so-called wet-spinning methods areemployed.

We have discovered that a very efiective distribution of thepigment-like particles can be secured and maintained in low viscositycellulosic solutions by thoroughly mixing the pigmentlike material witha portion of the solution of the cellulose compound in such manner as towet substantially all of the individual particles with the solution andthen introducing this mixture into the bulk of the solution and mixingboth portions together. This mixture we have found to be readilyeffected without such agitation of the bulk of the solution as wouldtend to break down its viscosity. Even in cellulosic solutions of verylow viscosity, the thorough distribution thus obtained is maintained inthe solution and in the filaments spun therefrom. -This embodiment of myinvention therefore consistsin the method of mixing the pigment-likematerial with a small portion of the cellulosic solution in such manneras to thoroughly wet the particles and this can best be effected bygrinding the solution and the particles together and then adding the themass material of the filament to be prepared with a portion of, forexample, a viscose solution, say about five percent of the solution, insuch manner as to wet substantially all of the individual particles andthen mix the pigmented portion of the solution with the balance of thesolution to distribute the pigment-like particles throughout the entiresolution.

Having now described our invention, what we claim as new and desire to.secure by Letters Patent, is:

1. The method of manufacturing artificial silk filaments which comprisesthoroughly mixing pigment-like particles with a low viscosity cellulosicsolution so as to wet substantially all of the particles with thesolution, mixing the mixture so obtained with the bulk of the cellulosicsolution from which the filaments are to be spun, whereby thepigment-like particles are incorporated in and widely distributedthroughout the cellulosic solution, and thereafter spinning saidsolution to form artificial silk filaments.

2. The method of manufacturing artificial silk filaments as set forth inclaim 1, in which the cellulosic solutions are viscose solutions.

3. The method of manufacturing artificial silk filaments as set forth inclaim 1, in which the pigment-like particles are titanium dioxide.

4. The method of manufacturing artificial silk filaments as set forth inclaim 1, in which the cellulosic solutions are viscose solutions and inwhich the pigment-like particles are titanium oxide.

HARRY P. BASSETI. JAMES H. TORRENCE.

mixture thus prepared to the bulk of the'cellulosic

